Treatment of cellulosic textile material with 1, 3-dimethyl-4, 5-dihydroxy-2-imidazolidinone



United States Patent 3,112,156 TREATMENT OF CELLULOSIC TEXTILE MATE- RIAL WITH l,3-D[METHYL-4,5-DIHYDROXY-2- IMIDAZOLIDINONE Sidney L. Vail and Paul J. Murphy, Jr., New Orleans,

La., assignors to the United States of America as represented by the Secretary of Agriculture No Drawing. Filed Oct. 7, 1960, Ser. No. 61,323 4 Claims. (Cl. 8-116.3) (Granted under Title 35, US. Code (1952), sec. 266) A nonexclusive irrevocable royalty-free license in the invention herein described, throughout the world for all purposes of the United States Government, with the power to grant sub-licenses for such purposes, is hereby granted to the Government of the United States of America.

This invention relates to the treatment of cellulosic textile material to produce textiles having improved properties. More specifically, the present invention relates to new textile treating agents and a method of treating cellulosic textile fabrics with these agents whereby the fabrics are rendered resistant to wrinkling, have improved resiliency, and possess wash-and-wear properties. Moreover, the fabric so treated may be laundered by procedures usually employed with untreated textiles of the same type, which procedure can include the use of hypochlorite bleaching agents without suffering discoloration or severe loss in strength either in the bleaching operation or on subsequent ironing.

Fabrics composed of cellulosic fibers such as cotton, rayon, and the like have full resiliency and consequently when in use tend to become wrinkled and acquire a mussed or unpleasant appearance. In order to overcome this objectionable property it has been the practice to treat cellulosic fabrics with various agents designed to produce wrinkle resistant and wash-and-wear fabric. One of the type agents used for this purpose is the l,3-dimethylol-4,5-dihydroxy-2-imidazolidinone produced by the reaction of the 4,5-dihydroxy-2-imidazolidinone and formaldehyde. Also another agent which is widely used of this type is l,3-dimethylol-2-imidazolidinone (DMEU). It is considered that multiple washings hydrolyze these finishes and form sites which will have a tendency toward tendering when the fabric is bleached with hypochlorite and ironed. (Ref. Nuessle, A. C., Textile Inds. 123, No. 10, 116 (1959).)

We have reacted 4,5-dihydroxy-2-irnidazolidinone, by itself, with cotton cellulose and found that fabrics treated with this agent yellow during curing. This is illustrated in Example 3 herein. Also, fabrics finished in this manner show poor resistance to hypochlorite bleaching agents as shown in the so-called scorch test. This damage is to be expected because of the free NH groups which are present in this agent. Consequently, this treating agent cannot be used to produce acceptable white wash-and-wear cellulosic fabrics. A primary object of this present invention is to produce a new Z-imidazolidinone which without reaction with formaldehyde can be applied to cellulosic textiles from an aqueous solution.

Another object of this invention is to provide a process for the treatment of textile fabrics composed mainly of cellulose with a new type of Z-imidazolidinone treating agent whereby the fabric acquires the property of in- 3,112,156 Patented Nov. 26, 1963 creased resiliency and wrinkle resistance, and which properties are retained after repeated launderings. It is furthermore an object of this invention to provide such a treatment whereby the treated fabrics, with the properties described, may be laundered repeatedly by ordinary procedures, which procedures may include the use of hypochlorite bleaching agents, without suffering discoloration or loss in strength in the laundering procedures or subsequent treatments greater than occurring on untreated fabrics.

Another object of this invention is to provide a finished fabric which is resistant to acid hydrolysis, one that does not lose its properties during laundry sours, as is sometimes the case with DMEU finished fabrics.

In general, these and other objects of the invention are accomplished by treating the cellulosic textile with an aqueous solution containing essentially monomeric 1,3-dimethyl-4,5-dihydroxy-2-imidaz;olidinone produced by the reaction of glyoxal and 1,3-dimethylurea and having the following structure:

As evidenced by the above structural formula NH groups cannot be formed unless the ring structure is broken. In this manner the formation of chloroamines is avoided as long as the ring is intact. Obviously this is not the case with finishes prepared from the 4,5-dihydroxy-Z-irnidazolidine or from the Z-imidazolidinone.

The 1,3-dimethyl-4,5-dihydroxy-Z-imidazolidinone used for the treatment of cellulosic textiles in the process of this invention can be conveniently obtained by the reaction of glyoxal and 1,3-di1nethylurea in a concentrated aqueous media under slightly alkaline conditions. It is preferred to use slightly greater than stoichiometric quantitles of the 1,3-dimethylurea in said reaction. More than 2 moles to 1 of the urea to the di-aldehyde is considered wasteful. A pH of the solution in the order of from 7 to 9 is preferred. However, it has been found the higher pHs within this range tend to give precipitation of the desired product more rapidly than the lower pHs. It is generally preferred to conduct the reaction at a temperature ranging from about room temperature (approximately 20 C.) to about 40 C. After stirring from about 4 to 24 hours, the solution is placed in a refrigerated compartment and cooled until the product has crystallized. This product as formed in the reaction mixture is suitable for direct treatment with cellulosic fabrics. However, additional purification can be obtained by recrystallization from solvents such as the mon-oethyl ether of ethylene glycol, ethyl alcohol, or water. The product is then dried and stored at room temperatures until used.

The padding solution is prepared by meerly dissolving the 1,3-dimethyl-4,5-dihydroxy-Z-imidazolidinone in the required quantity of water together with an acidic polymerization catalyst. The catalyst can be an acidic substance or a substance producing acidity at elevated temperatures. The concentration of the agent present in the diluted solution can be varied depending on the particular textile processing conditions used, the type of textile being treated, and the properties desired in the finished textile. It is generally preferred to use about to by weight of the agent in the diluted treating solution. A metal salt of a strong mineral acid is a particularly suitable acidic catalyst to add to the diluted treating solution for the process of the present invention. Magnesium chloride, zinc nitrate, and zinc fiuoborate are examples of particularly suitable catalysts. From about 0.5% to about 5% by weight of the acidic catalyst is generally preferred.

Treatment of the cellulosic textile material according to the process of this invention comprises uniformly impregnating (thoroughly wetting) the textile with the above described diluted treating solution, mechanically removing excess liquid, then drying and curing the goods. All of these steps can be conveniently carried out with conventional textile finishing equipment. The wet pickup (increase in weight of the textile upon wetting), after mechanically removing excess liquids should be preferably from about 70 to 80% when using the preferred treating solution. Adjustment to the desired wet pickup can be conveniently achieved by passing the impregnated textile through squeeze rolls or the like. The drying time and temperature are not critical, but it is preferred to dry the wet textile, adjusted to the desired pickup, at relatively low temperatures from about 60 to 100 C. until the textile is dry to the touch. After drying, the textile is cured by subjecting it to a higher temperature, from about 100 to 160 C. from about V2 to minutes to cause reaction or in some cases further reaction of the applied materials. In the curing operation the longer time is used with the lower curing temperature. Curing temperatures above about 160 C. are generally not desirable since there is danger of degradation of cellulose at the higher temperatures.

Following the curing operation, it is preferable to water wash the treated textiles to remove any unreacted materials. The washing operation can be carried out using the procedures and equipment conventionally employed for the washing of textiles. After it is washed and dried, the treated textile has the same appearance as the original untreated textile and its feel is almost essentially unchanged, but the treated fabric possesses resiliency,

wrinkle resistance, and the other desirable properties previously described. In addition to being employed as the sole agent in the treating soltuion of the present invention, the new agent may also be used in blends with various conventional treating agents to produce economical and improved textile cellulosic products.

The process of this invention may be used to treat substantially any hydrophilic fibrous cellulosic material such as cotton, rayon, ramie, jute, and the like which can be impregnated with a liquid, dried, and cured. The following examples are given by way of illustration and are not by way of limitation of invention. The detailed procedures given in the examples are illustrative, and are not the only specific conditions for the production of an acceptable finished textile. Many variations or additions within these procedures may be made as will be readily apparent to those skilled in the art. In the examples all parts and percentages are by weight unless noted otherwise. The fabrics are tested by the following methods: wrinkle recovery angle, Monsanto Method, American Society for Testing Materials (ASTM) Test 1295-53T; breaking strength, ASTM Test D3949; damage caused by retained chlorine, American Association of Textile Chemists and Colorists Tentative Test Methods 691952 (Scorch Test). Also the fabrics were subjected to ten home washings. using hypochlorite bleach. The home washes were performed in an agitator-type home automatic washer with a household detergent, 0.02% available chlorine in hot water, and followed by drying in a tumble dryer. A Hunter Multipurpose Refiectometer with the blue filter was used to measure the yellowing of the hypochlorite bleached fabrics. Five AATCC launderings as described in AATCC Test 14-53 were used as a preliminary to the chlorine scorch test to determine whether a particular finish will be durable to conditions which may be encountered during service.

EXAMPLE 1 l,3-dirnethyl-4,5-dihydroxy-2-imidazolidinone was prepared in the following manner: 193.5 grams of glyoxal (%-tcchnical grade) was adjusted to a pH of 8.0 to 8.5 with 25 sodium hydroxide (solid sodium carbonate was also often used). To this was added 132 grams of 1,3-dimethylurea. The solution was stirred at room temperature for roughly four hours and then refrigerated at 5 C. to l5 C. As crystals appeared in quantity, they were filtered off and dried in a vacuum oven at temperatures below Higher temperatures for drying have been used but these gave indications of decomposition. This material could be used as is for producing wrinkle resistant fabrics or purified further by recrystallization. The l,3-d.i1nethyl-4,5-dihydroxy-2-imadazolidinone after recrystallization had a melting point of 132 to 134 C. The product was found by analysis to contain nitrogen 19.16%, carbon 41.35%, and hydrogen 6.90%. The values calculated for C H O N are as follows: nitrogen 19.17%, carbon 41.09%, and hydrogen 6.90%.

EXAMPLE 2 4.8 grams of l,3-dimethyl-4,S-dihydroxy-Z-imidazolidinone prepared as described in Example 1 was dissolved in 42.3 grams of water. To this was added 0.9 gram of a 40% solution of zinc fluoroborate. A sample of 80 x 80 cotton print fabric was dipped in the treating solution and padded to give about 70 to 80% increase in weight of the fabric (i.e., wet pickup of 70 to 80% The wet fabric was then dried 7 minutes at C. and cured for 160 C. for 3 minutes. This treatment was followed by an afterwas h in warm water with a nonionic detergent added, and then tumble dried. The finished fabric was pleasant to the touch and was wrinkle resistant, possessing a crease recovery angle of 270 (sum of the determinations in warp and fill direction). The original untreated fabric had a crease recovery angle of only 180 (warp plus fill).

EXAMPLE 3 For comparison purposes, this same type of cotton print fabric was dipped in a treating solution containing 10% 4,5-dihydroxy-Z-imidazolidinone and with 0.5% zinc nitrate hexahydrate and 0.05% acetic acid. The fabric was padded to give about to wet pickup, dried as in Example 2, and cured for 3 minutes at C. After washing and drying this fabric possessed a crease recovery angle of 290. However, it was badly yellowed.

EXAMPLE 4 Also for comparison purposes a 7% solution of 1,3-dimethylol-Z-imidazolidinone containing 0.5% zinc nitrate hexahydrate and 0.05% acetic acid was applied to cotton print fabric and processed in the same manner as described in Example 2. The finished fabric was pleasant to the touch and was wrinkle resistant possessing a crease recovery angle of 299.

The various treated fabrics in the above examples as well as other similarly prepared fabrics were subjected to a series of 10 home washes and five AATCC washes and the effect of these Washes on the properties of the finished fabric are shown in Table I.

used effectively employing concentration from 7.6 to 10% to produce wrinkle resistant fabrics.

ORA

Reilee tanee 1 Crease Recovery Angle. To compare the various finishes under investigation with respect to their resistance to hydrolytic removal under acidic conditions, the finished fabrics were exposed to solutions of a range of acid pHs for 30 minutes at 40 C. The changes undergone in wrinkle recovery are shown in Table II.

Table II EFFECT OF pH ON HYDROLYSIS OF WRINKLE-RESISTANT It is evident from these data that the 1,3-dimetl1y1-4,5- dihydroxy-Z-imidazolidinone and the 4,5-dihydroxy-2- irnidazoli-dinone finishes are more resistant to acid bydrolysis than the 1,3-dimethylol-Z-imidazolidinone finish. Also, it is shown in Table I the finished fabric from 1,3- dimethyl-4,S-dihydroxy-Z-imidazolidinone after ten home washes in bleach and 5 AATCC washes still retains an adequate crease recovery angle and is more resistant to chlorine damage than a similar fabric from 1,3-dimethylol-2-imidazolidinone. Also, it is shown in Table I the fabrics finished with this new agent show no tendency to yellow after washes in hypochlorite bleach. The data in Table I also indicate that the new agent can be We claim:

1. A process for treating a cellulosic textile material to render it resistant to wrinkling, to improve its resiliency, and to impart wash-and-wear properties to it, comprising impregnating the cellulosic textile material to a wet pickup of about from to by weight with an aqueous solution containing about from 5% to 15% by weight of essentially monomeric 1,3-dimethyl-4,S-dihydroxy-Z-imidazolidinone and about from 0.5% to 5.0% by weight of an acidic polymerization catalyst, curing the impregnated material at a temperature of about from C. to C. and removing unreacted reactants from the resulting impregnated, cured cellulosic textile material.

2. The process of claim 1 wherein the acidic polymerization catalyst is zinc fluoroborate.

3. The process of claim 1 wherein the acidic polymerization catalyst is zinc nitrate hexahydrate.

4. The process of claim 1 wherein the acidic polymerization catalyst is magnesium chloride.

References Cited in the file of this patent UNITED STATES PATENTS 2,731,364 Reibnitz et a1 Jan. 17, 1956 2,764,573 Reibnitz et al. Sept. 25, 1956 2,785,176 Vebra Mar. 12, 1957 2,847,418 Steele Aug. 12, 1958 2,876,062 Torke et al. Mar. 3, 1959 2,965,436 Domenico et al Dec. 20, 1960 OTHER REFERENCES Wayland: Textile Research Journal, February 1959, pp. -179, particularly page 175. 

1. A PROCESS FOR TREATING ACELLULOSIC TEXTILE MATERIAL TO RENDER IT RESISTANT TO WRINKLING, TO IMPROVE ITS RESILIENCY, AND TO IMPART WASH-AND-WEAR PROPERTIES TO IT, COMPRISING IMPREGNATING THE CELLULOSIC TEXTILE MATERIAL TO A WET PICKUP OF ABOUT FROM 70% TO 80% BY WEIGHT WITH AN AQUEOUS SOLUTION CONTAINING ABOUT FROM 5% TO 15% BY WEIGHT OF ESSENTIALLY MONOMERIC 1,3-DIMETHYL-4,5-DIHYDROXY-2-IMIDAZOLIDINONE AND ABOUT FROM 0.5% TO 5.0% BY WEIGHT OF AN ACIDIC POLYMEIZATION CATALYST, CURING THE IMPREGNATED MATERIAL AT A TEMPERATURE OF ABOUT FROM 100*C., TO 160*C. AND REMOVING UNREACTED REACTANTS FROM THE RESULTING IMPREGNATED, CURED CELLULOSIC TEXTILE MATERIAL. 